The present invention relates to a programmable automatic monitoring and display system for use with a digging machine whereby to monitor the excavation of a hole having a preset desired depth and a slope pitch angle from ground level.
It is known in the art to provide automatic monitoring systems in association with digging machines whereby to preset in a computer a predetermined depth for an excavation and upon excavating the hole, signals are provided to the operator concerning the position of the digging teeth of the bucket relative to the desired depth. Accordingly, the operator is continuously aware of the depth of the hole, particularly, in instances where the position of the bucket teeth is not visible. It is important when excavating holes for foundations, etc., that the depth of the hole be maintained as close as possible to the desired depth. Most methods are manual and labor intensive as an assistant is required to effectuate the measurements and relay this information to the machine operator. Such a method is also dangerous since the assistant is exposed to all sorts of hazardous situations and particularly when the weather is inclement.
U.S. Pat. No. 4,491,927 discloses a depth monitoring system of the type as disclosed in the present application whereby a computer is utilized to compute the trigonometric relationship between the boom, dipper stick and bucket. In that particular patent, the trigonometric equation involves the addition of three angular relationships between the boom, dipper stick and the bucket. The depth of the hole is also measured from the top edge of a vertical surveyor stake implanted in the ground to serve as a reference guide. The stick has a predetermined height above the level of the ground and this height is subtracted by the computer from the inputted measurements. Because the system utilizes three sensors, the set-up of the computer is more complicated and time consuming. Also, it is susceptible to errors as the alignment of the bucket with the dipper stick is far away from the operator, who sits in the cabin of the machine, and it is difficult to align these perfectly by using the eye. Although this system is adequate for excavating holes primarily for foundations, it cannot excavate slope angles associated with the hole or slope excavation for existing holes or trenches, ditches, etc.
It is a feature of the present invention to provide an automatic monitoring and display system in combination with a digging machine for excavating a hole having both a predetermined depth and an excavation slope pitch from ground level and which substantially overcomes the above-mentioned disadvantage of the prior art.
Another feature of the present invention is to provide an automatic monitoring and display system in combination with a digging machine for excavating a hole having an excavation slope pitch from ground level to hole depth and wherein the system utilizes only two inclinometer sensors associated with a boom, a dipper stick and a bucket, all interconnected together and to the machine by three pivot points.
Another feature of the present invention is to provide an automatic monitoring and display system in combination with a digging machine for excavating a hole having an excavation slope pitch from ground level to hole depth and wherein the operator of the digging machine can reset a zero reference signal at any ground point to excavate a hole as well as a slope pitch from either the top ground level or the bottom ground level at the base of the excavation.
It is a further feature of the present invention to provide an automatic monitoring and display system in combination with a digging machine for excavating a hole having an excavation slope pitch from ground level to hole depth and wherein the bucket and dipper stick are aligned at a predetermined position during the set-up mode by visual aligning markers provided on the bucket and dipper stick.
According to the above features, from a broad aspect, the present invention provides an automatic monitoring and display system in combination with a digging machine for excavating a hole having a predetermined depth and an excavation slope pitch from ground level to hole depth. The digging machine has a boom with a first pivot at a near end connected to a machine body. A dipper stick is pivotally connected to a far end of the boom by a second pivot. A bucket is pivotally connected to a far end of the dipper stick by a third pivot. The bucket has digging teeth at an extreme lower edge thereof. A first inclinometer sensor is secured to the boom close to the first pivot. A second inclinometer sensor is secured to the dipper stick close to the second pivot. A first aligning marker is provided on the far end of the dipper stick and disposed for visual access to a machine operator position. A second marker is provided on the bucket and disposed for alignment with the first marker. The first and second markers, when aligned, position the digging teeth in alignment with a longitudinal axis of the dipper stick passing through the second and third pivot. Memory storage means is provided for storing signals indicative of boom length between the first and second pivot, combined length of the dipper stick and the bucket from the second pivot to the digging teeth of the bucket, and mathematical information for calculating excavation depth and excavation slope angle. Processor means is provided for processing position signals received from the first and second inclinometer sensors relative to a preset virtual zero signal. The processor means feeds resultant signals to a display processor means for providing a visual display to a machine operator indicative of excavation depth and excavation slope pitch. A console has a first function switch means for programming for desired hole excavation depth and a second function switch means for programming desired slope pitch.